GPRS, UMTS, and LTE systems are an evolution of the global system for mobile communications (GSM) standard to provide packet switched data services to GSM mobile stations. Packet-switched data services are used for transmitting chunks of data or for data transfers of an intermittent or bursty nature. Typical applications for Third Generation Partnership Project (3GPP) packet service include Internet browsing, wireless e-mail, video streaming, and credit card processing, etc. used by human users.
Organizations both private & government that are local & global are looking for new and innovative ways to manage their business & operations at an optimum cost structure. As the cost of connectivity starts to drop precipitously, they are looking to take advantage of huge efficiency gains through access to data for processing and analysis in an optimized way, which previously was only available through costly human intervention.
These new applications and markets start to emerge that take advantage of ubiquitous cellular coverage. Even though the underlying radio technology continues to evolve from 2G, 2.5G, 3G and now LTE, new innovation is being developed to take advantage of this infrastructure in the form of smart devices and sensors that are creating new market opportunities for Mobile Network Operators (MNOs). Cellular networks are ideal in connecting millions of data collecting devices to the processing infrastructure. The opportunity to connect millions and even billions of devices is creating an exciting market opportunity commonly defined as machine to machine (M2M).
However, as MNOs look to seize this new market opportunity, there are many challenges in adopting the same practices and architecture that were designed for a very different human consumer market model. The cost structure is fundamentally different, the relationship with an Enterprise is fundamentally different and the impact on the network from non-human devices is fundamentally different.
Most machine to machine offerings currently in the market treat the cellular network as a transport pipe. While this approach is simple and can be deployed using existing cellular infrastructure, it ignores the fact that machine type communication needs are inherently different than those for a human subscriber. Lots of machine type communication is more signaling intensive than data intensive; i.e. the amount of data that is communicated between the device and the network is often times very small and there are many signaling exchanges to establish the data channel between the device and the network. Furthermore, a number of machine type communication (MTC) devices can be a lot bigger than that of single user subscribers, e.g. a smart meter deployed in a county could be millions. As the number of connected devices goes up, the network would succumb to signaling overload and possible other forms of congestion, especially in the radio network, impacting the quality of services for high revenue generating human users, not just the machine type devices.
FIG. 1 is a block diagram illustrating how high priority human user devices and low priority machine type devices/opt-in human user devices are handled the same way over GPRS network architecture. Referring to FIG. 1, machine type devices/opt-in human user devices 101 and high priority human user devices, e.g. smart phones 102, are communicatively coupled to a packet core network 110. For example, machine type device/opt-in human user devices 101 and high priority human user devices 102 are coupled to the mobile network 110 via a third generation (3G) radio access network through, for example, nodeB (NB) and radio network controller (RNC) for 3G network or enhanced NodeB (eNB) 104 for LTE network, a serving GPRS support node (SGSN) for 3G network or serving gateway (S-GW)/mobility management entity (MME) 105 for LTE network, and a gateway GPRS support node (GGSN) for 3G network or packet data network (PDN-GW) 106 for LTE network. In order for the MTC device 101 to communicate to a MTC application server located in other networks such as Internet and/or Enterprise premises 122, machine type devices 101 go through packet core network 110, which relays communications between a machine type user equipment (UE) 101 and a destination (e.g. Enterprise server 122).
The MTC devices/opt-in human user devices 101 and the high priority human user devices 102 are treated as one user equipment equally at the packet core network 110 and the radio network 104. When there are low priority MTC devices/opt-in human user devices 101 and the high priority human user devices 102 mixed in some areas, these devices compete for resources regardless of the priority or criticality. For example, both the low priority MTC devices/opt-in human user devices 101 and the high priority human user devices 102 start attach procedure 111 toward the radio network 104. The radio network 104 forwards the attach procedure messages 112 to the serving GPRS support node (SGSN) or Mobility Management Entity (MME) 105. SGSN or MME 105 performs the authentication 113 with Home Location Register (HLR)/Authentication Center (AuC) 107 for each device that requires access to the network. Once the authentication is successful, the SGSN or MME 105 sends attach accept response to the devices. It involves many message exchanges to complete one procedure, e.g. about 7 to 9 messages to complete the attach procedure per node. At the enB or NB 104, it needs to process about 7 messages before the UE is attached and during this time, the resources at the eNB or NB 104 are occupied for that device. Once all the resources at the eNB or NB 104 are used to process multiple procedures from multiple devices, the eNB or NB 104 cannot accept any new requests, i.e. it cannot allow any new devices until the procedures for other device(s) are completed and resource becomes available 114.
If there are lots of low priority MTC devices/opt-in human user devices 101 in the area, high priority human user devices 102 need to compete with those low priority devices 101 for radio network resources. Once the radio network resource is fully occupied, the request for access from the UE will be dropped at the radio network. In the case where there are 50:50 number of low priority devices and the high priority devices, and if the low priority devices 101 have requested the access at the same time and occupies the radio network resources, some of the high priority devices 102 as well as the low priority devices 101 will be rejected from access to the radio network until a whole procedure between the device and the network is completed, which takes up about 7 to 10 message exchanges in total.
The problem of this model is that the high priority devices and the low priority devices will be treated the same and the high priority human user devices 101 and/or critical MTC devices will be competing with low priority non-critical MTC devices or opt-in low priority human user devices. Radio spectrum is an expensive and rare resource for the mobile operators and supporting the low priority devices could result in deteriorated quality of service for the high priority users, especially as the number of MTC devices grow exponentially, to millions and billions. There are some attempts in standard bodies to address this issue by upgrading the radio network devices 104 and the low priority devices 101. However, since this involves change at the devices 101 and the radio network devices 104, it will be very costly for operators and it will also take time to actually deploy the proposed solution.